WIP - First stab at creating a BodyDelegate type

[grumpydev]

Prerequisites

• I have written a descriptive pull-request title
• I have verified that there are no overlapping pull-requests open
• I have verified that I am following the Nancy code style guidelines
• I have provided test coverage for my change (where applicable)

Description

Initial stab at pulling out the body delegate to its own type to allow for casts to/from the actual async and non-async delegate signatures - idea being we patch up everything by adding a cast to Action to make it build (unfortunately implicit casts and delegates still need an explicit cast), then we can work through bit by bit making them async, then remove the cast option from the sync delegate type at a later date.

Already fixed up the Nancy project itself, which shows both "asyncing" the bits that make sense, and just straight casting the bits that don't (such as when writing a string).

[jchannon]

This is in the wrong location, needs to be under ./Nancy

[grumpydev]

shrug VS2015 is garbage, what can I say? :)

[jchannon]

../Nancy required

[thecodejunkie]

@grumpydev @jchannon yeah unfortunately there is a bit of fud right now if you add new files.. due to and old bug with VS tooling when project.json and *.csproj files existed side by side https://github.com/dotnet/corefx/issues/4544 I'm trying to figure out if it has been resolved. If it has then we should revert the <projectname>.MSBuild folder change we made as a workaround. For the time being we manually have to move the files to the correct folder and update the *.csproj to link them

[thecodejunkie]

@grumpydev can you rebase plz?

[thecodejunkie]

👀 rebase, pretty please? 😄